Toothbrush

ABSTRACT

According to this invention, a toothbrush is provided having a head and a handle having a grip portion, disposed along a longitudinal axis, the head having britstles exending from a face thereof (&#34;the bristle face&#34;) in a general bristle direction, between the grip portion and the head of the toothbrush there being an integral region of folds having a fold axis in a direction lateral to the longitudinal axis, one or more limbs of the folds being penetrated by an elastomeric material which passes through an aperture in the limb, characterized by the elastomeric material being exposed on both sides of the penetrated limb.

BACKGROUND OF THE INVENTION

This invention relates to toothbrushes, in particular to toothbrusheshaving a flexible region between the head and the handle.

Toothbrushes are known in which there is a flexible region, or aflexibility-modifying region, between the head and the handle. One typeof such a toothbrush is disclosed in EP 0336641 A in which there is anintegral region of "V"-shaped folds between the head and the handle, ofwhich the flexibility may be modified by mans of a longitudinal core ofthe plastics material of which the toothbrush is made. Another type ofsuch a toothbrush is disclosed in DE 39 23 495 A, in which there are aseries of laterally oriented slots in the handle, filled with anelastomeric material so as to modify the flexibility. WO 92117093discloses a toothbrush in which the flexibility of the head is modifiedby the presence of lateral slots filled with an elastomer, and WO92/17092 discloses a toothbrush in which a flexible link is formedbetween the head and neck by a cut out, extending between the head andneck, and filled with an elastomer.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a modified, improved,version of such a toothbrush, in which such a folded region is made moreeffective in modifying the flexibility of the toothbrush, in aconstruction which enables a folded region of more precisely definedflexibility to be constructed.

According to this invention a toothbrush is provided having a head and ahandle having a grip portion, disposed along a longitudinal axis, thehead having bristles extending from a face thereof ("the bristle face")in a general bristle direction, between the grip portion and the head ofthe toothbrush there being an integral region of folds having a foldaxis in a direction lateral to the longitudinal axis, one or more limbsof the folds being penetrated by an elastomeric material which passesthrough an aperture in the limb, characterised by the elastomericmaterial being exposed on both sides of the penetrated limb.

The invention enables the folded region to be in effect a compositestructure of the toothbrush head, handle and fold material, which ispreferable a mouldable plastics material, and an elastomeric material.This enables an improved degree of control of the flexibility of thefolded region relative to a folded region made without the elastomericmaterial, e.g. entirely of plastics material. The construction alsoenables the toothbrush to have an improved degree of flexibility aboutflex axes such as torsional flexibility.

The fold axis is defined as the axis between the limbs of the folds andextending perpendicular to the plane in which the folds lie. The foldsmay be substantially "V" or "U" shaped, so that two of such folds joinedend to end form a substantially "W" or "S" shaped folded region. Thefold axis is preferably in a lateral direction substantiallyperpendicular to the longitudinal axis of the toothbrush, and also tothe general bristle direction. The folded region may for example includebetween two and seven, preferably five of such folds, on longitudinallyalternating sides of the longitudinal axis, in the general manner of thetoothbrush of EP 0336641 A.

Preferably all of the limbs are penetrated by the elastomeric material,such that the elastomeric material forms a longitudinal core extendingthe entire length of the folded region. The aperture(s) in thepenetrated fold(s), and hence the elastomeric material in the aperture,may correspond in cross sectional shape to the cross sectional shape ofthe toothbrush in the penetrated region. The penetrated region ispreferably generally quadrilateral, e.g. rectangular or square, whichmay have rounded corners. The dimensions of the aperture may be asubstantial proportion of the cross sectional dimensions of the limb,for example 25% or more, e.g. 50% or more of the width of the limb.

At either or both ends of the folded region the elastomeric material mayextend longitudinally beyond the folded region. The elastomeric materialmay extend to the grip portion of the toothbrush into an integralelastomeric grip pad of the kind disclosed in EP 0336641, the contentsof which are included herein by way of reference, for example along amoulding conduit. Towards the head of the toothbrush the elastomericmaterial may extend into a flexible link between the head and the handleof the toothbrush of the kind disclosed in WO 92/17092 or EP 0613636 A,the contents of which are included herein by way of reference, again forexample along a moulding conduit.

The elastomeric material is exposed on both sides of the penetratedlimb(s), so as to be present and visible in the concavity of the fold onboth sides of the penetrated limb(s). In the concavity the elastomericmaterial may remain of the same width as it has in the aperture(s), orits width may increase up to substantially the entire width of theconcavity.

The aperture(s) may be extended outwards to the outside surface of theouter bend of the folds, i.e. on the other side of the fold from theconcavity. On this outer surface the aperture may open into a mouldingconduit extending longitudinally, for example linking a grip pad ofelastomeric material to a flexible link between the head and the neck ofthe toothbrush.

The elastomeric material is preferably bonded to the material of thetoothbrush where the two are in contact. Suitable elastomeric materialsand bonding techniques which can achieve this are known in the art andare used commonly in marketed toothbrushes. The elastomeric material ispreferably one which is suitable for use in the grip pad or the flexiblelink as mentioned above, so that by means of moulding channels a singleinjection port can be used to injection mould the elastomeric parts ofthe toothbrush. The elastomeric material is preferably of a contrastingcolour to the material of the other parts of the toothbrush, so that thenovel construction of the toothbrush can be emphasised by thecontrasting appearance. For example the handle and head of thetoothbrush may be made of white plastics material, and the elastomericmaterial may be contrastingly coloured. Suitable plastics materials forthe head and handle of the toothbrush are disclosed in EP 0336641 A.

The head and handle of the toothbrush of the invention may be of a knownconstruction. For example the head may have bristles distributed uponits bristle face in discrete tufts, or the bristles may be distributedin a pattern such as that disclosed in PCT/EP 94/02828, the contents ofwhich are included herein by way of reference, and may be linked to thehandle by a flexible link as described above, and the handle may havethe above-mentioned grip pads.

The toothbrush of this invention may be manufactured using a generallyknown process, in which a plastics material frame or skeleton is firstmade by injection moulding, including the folded region and theaperture(s), and the elastomeric material is then injection moulded inunder conditions which result in fusion with the plastics material.

The invention therefore in a further aspect provides a process formanufacturing a toothbrush as described herein, in which a plasticsmaterial frame or skeleton is made, and elastomeric material is mouldedaround the frame or skeleton under conditions which result in fusionwith the plastics material.

The invention therefore in a further aspect provides a frame or skeletonsuitable for use in such a process to manufacture a toothbrush asdescribed herein.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described by way of non-limiting example onlywith reference to the following drawings.

FIG. 1 shows a top view of one embodiment of a toothbrush of thisinvention.

FIG. 2 shows a bottom view of the toothbrush of FIG. 1.

FIG. 3 shows a side view of the toothbrush of FIG. 1.

FIG. 4 shows a part longitudinal sectional view of the toothbrush ofFIG. 1.

FIG. 5 shows a cross sectional view of the toothbrush of FIG. 1.

FIG. 6 shows a bottom view of a further embodiment of the toothbrush ofthis invention.

FIG. 7 shows a part longitudinal sectional view of the toothbrush ofFIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 5, a toothbrush comprises a bristle bearing head1 and a handle 2 disposed along a longitudinal axis A--A. The bristles 3extend from a face of the head 1 in a general bristle direction B. Thehandle 2 includes elastomeric grip pads 4 of a type as disclosed in EP0366441 B.

Between the head 1 and the handle 2 is a folded region 5 comprising anumber of "U" shaped folds 6, the head 1, handle 2 and region 5 beingintegrally injection moulded of plastics material. The fold axis C--Cextends perpendicular to the longitudinal axis A--A and the generalbristle direction B, i.e. out of the plane of FIGS. 3 and 4, this planebeing that in which the limbs 7 of the folds lie. Two of the foldsjoined end to end form an "S" fold.

Each of the limbs 7 has an aperture 8 passing completely through fromone side of the limb to the other. The position of the aperture 8 isshown by a dotted line 8A in FIGS. 1 and 2. Passing through eachaperture is an elastomeric material 9 in the form of a longitudinal coreextending the entire length of the folded region 5. As seen in the crosssection at C--C in FIG. 5, the cross sectional shape of the core 9 isquadrilateral, corresponding generally to the cross section of thefolded region 5. The elastomeric material 9 is exposed on both sides ofthe limbs 7, and is present in the concavities 10 between the limbs,where it is of substantially the same width as the apertures 8, althoughit could extend to substantially the entire width of the adjacent limb7.

At the end of the folded region 5 facing the handle 2 the elastomericmaterial 9 extends to integrally join the elastomeric material of thegrip pad 4, and at the end of the folded region 5 facing the head 1 theelastomeric material 9 also extends at 11.

The elastomeric material 9 is bonded to the plastics material of thetoothbrush, and towards the grip pad 4 and at 11 it, occupies a mouldingconduit 12 in the handle. The elastomeric material 9 is of a differentand contrasting colour to that of the handle 2.

Referring to FIGS. 6 and 7, a toothbrush is shown, parts correspondingto features shown in FIGS. 1 to 6 being correspondingly numbered. Theposition of the aperture 8 is shown with a doted line 8A in FIG. 6. Inthe toothbrush of FIGS. 6 and 7 the aperture 8 extends in a narrowchannel to the outer surface of the folds 6 to form slot shaped mouldingconduits 13, filled with the elastomeric material 9, and linking thegrip pad 4 and the elastomeric material in the concavities 10. Althoughshown as narrow slots 13 the conduits 13 could extend to substantiallythe whole width of the outer surface of the folds 6.

At the end of the folded region 5 facing the head 1 the elastomericmaterial 9 extends in moulding conduit 14 to integral join a flexiblelink 15 of the type shown in EP 0613636 A although other types offlexible link are possible. Side views and the top view of thetoothbrush of FIGS. 6 and 7 are substantially the same as FIGS. 1 and 3.

The toothbrushes of FIGS. 1 to 7 are made by firstly injection mouldinga skeleton of plastics material making up the plastics material parts ofthe head 1, handle 2 and folded region 5, then moulding in theelastomeric material 9 under conditions such that the elastomericmaterial and plastics material fuse together and bond.

What is claimed is:
 1. A toothbrush having a head (1) and a handle (2)having a grip portion, disposed along a longitudinal axis, the headhaving bristles (3) extending from a face thereof ("the bristle face")in a general bristle direction, between the grip portion and the head ofthe toothbrush there being an integral region of folds (5) having a foldaxis in a direction lateral to the longitudinal axis, one or more limbs(7) of the folds (6) being penetrated by an elastomeric material (9)which passes through an aperture (8) in the limb, characterised by theelastomeric material (9) being exposed on both sides of the penetratedlimb (7).
 2. A toothbrush according to claim 1 characterised in that thefolds (6) are substantially "V" or "U" shaped, so that two of such folds(6) joined end to end form a substantially "W" or "S" shaped foldedregion (5), and the fold axis is in a lateral direction substantiallyperpendicular to the longitudinal axis of the toothbrush, and also tothe general bristle direction.
 3. A toothbrush according to claim 1characterised in that all of the limbs (7) are penetrated by theelastomeric material (9), such that the elastomeric material (9) forms alongitudinal core extending the entire length of the folded region (5).4. A toothbrush according to claim 1 characterised in that theaperture(s) (8) in the penetrated fold(s) (5), and hence the elastomericmaterial (9) in the aperture (8), corresponds in cross sectional shapeto the cross sectional shape of the toothbrush in the penetrated region(5).
 5. A toothbrush according to claim 1 characterised in that thedimensions of the aperture (8) are 25% or more of the width of the limb(7).